[AK4685]
■ Digital Volume Control
The AK4685 has channel-independent digital volume control (256 levels, 0.5dB step). The IATL7-0, IATR7-0 bits set
the volume level of ADC channel (Table 13). The OAT1L7-0, OAT1R7-0, OAT2L7-0 and OAT2R7-0 bits set each DAC
channel (Table 14).
IATL7-0,
Gain
IATR7-0
00H
01H
02H
:
+24dB
+23.5dB
+23.0dB
:
2FH
30H
31H
+0.5dB
0dB
-0.5dB
:
(default)
FEH
FFH
-103dB
MUTE (-∞)
Table 13. ADC Digital Volume (IATT)
OAT1L7-0,
OAT1R7-0,
OAT2L7-0,
OAT2R7-0
00H
Gain
+12dB
+11.5dB
+11.0dB
:
01H
02H
:
17H
18H
+0.5dB
0dB
(default)
19H
-0.5dB
:
FEH
FFH
-115dB
MUTE (-∞)
Table 14. DAC Digital Volume (OATT)
ATSAD (ATSDA) bits (Table 15, Table 16) control the transition time of attenuation. The transition between each
attenuation level is the soft transition. Therefore, the switching noise does not occur in the transition.
Mode
0
1
ATSAD
ATT speed
1061/fs
256/fs
(default)
0
1
Table 15. Transition time of attenuation (ADC)
Mode
0
1
ATSDA
ATT speed
1061/fs
256/fs
(default)
0
1
Table 16. Transition time of attenuation (DAC1/2)
MS1106-E-00
2009/08
- 24 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
